1. Technical Field
Embodiments of the present invention generally relate to environment based navigation systems for industrial vehicles and, more specifically, to a method and apparatus for automatically calibrating vehicle parameters.
2. Description of the Related Art
Entities regularly operate numerous facilities in order to meet supply and/or demand goals. For example, small to large corporations, government organizations and/or the like employ a variety of logistics management and inventory management paradigms to move objects (e.g., raw materials, goods, machines and/or the like) into a variety of physical environments (e.g., warehouses, cold rooms, factories, plants, stores and/or the like). A multinational company may build warehouses in one country to store raw materials for manufacture into goods, which are housed in a warehouse in another country for distribution into local retail markets. The warehouses must be well-organized in order to maintain and/or improve production and sales. If raw materials are not transported to the factory at an optimal rate, fewer goods are manufactured. As a result, revenue is not generated for the unmanufactured goods to counterbalance the costs of the raw materials.
Unfortunately, physical environments, such as warehouses, have several limitations that prevent timely completion of various tasks. Warehouses and other shared use spaces, for instance, must be safe for a human work force. Some employees operate heavy machinery and industrial vehicles, such as forklifts, which have the potential to cause severe or deadly injury. Nonetheless, human beings are required to use the industrial vehicles to complete tasks, which include object handling tasks, such as moving pallets of goods to different locations within a warehouse. Most warehouses employ a large number of forklift drivers and forklifts to move objects. In order to increase productivity, these warehouses simply add more forklifts and forklift drivers.
In order to mitigate the aforementioned problems, some warehouses utilize equipment for automating these tasks. As an example, these warehouses may employ automated industrial vehicles, such as forklifts, to carry objects on paths. When automating an industrial vehicle, a key requirement is the ability to accurately locate the vehicle in the warehouse. To achieve such location, a plurality of sensors are frequently used to measure the position. However, it is necessary to account for uncertainty and noise associated with the sensor measurements. For example, vehicle parameters (e.g., wheel diameter) change over time due to various reasons, such as wear and tear, seasonal conditions and/or the like. Vehicle parameter changes can cause inaccuracies with sensor device measurements, which are reflected as a bias, for example, during vehicle pose prediction. Without calibration, the automated vehicle will continue to perform localization and mapping using vehicle parameters which no longer reflect the state of the vehicle, causing significant errors in automated industrial vehicle navigation and operation.
Therefore, there is need in the art for a method and apparatus for automatically calibrating vehicle parameters to enhance automated industrial vehicle navigation.